A commonly-used passive polarized 3D display device, as shown in FIG. 1, comprises: a backlight unit 1, a first polarizer 2, an array substrate 3, a color filter substrate 4, a second polarizer 5, and a patterned retarder film 6, which are disposed sequentially. On a side of the color filter substrate 4 facing the array substrate 3, a black matrix is provided, and the black matrix includes a plurality of matrix strips 41. Herein, a width of a matrix strip is h, and a sum of a thickness of the color filter substrate and a thickness of the second polarizer is D. In FIG. 1, an angle A is a maximum correct light transmitting angle of one pixel region between adjacent matrix strips 41 on a color filter surface of the color filter substrate 4, and an angle B is a vertical visual angle of the 3D display device, and is also an angle after the angle A is refracted. Therefore, according to the law of refraction, it can be known that half of the vertical visual angle B/2=arc sin (refractive index×sin(A/2)), where the angle A=2 arc tan(h/2D), and the refractive index is a constant value, and generally is assigned a value of 1.5.
In the range of the vertical visual angle B, a user can see an ideal three-dimensional image; out of the range of the vertical visual angle B, due to crosstalk between images in left and right eyes, the obtained three-dimensional image is poor in quality. If it is an ordinary display device, the user's viewing angle is relatively small, so the quality of an obtained image is degraded. In order to expand the range of vertical visual angle, in the prior art, a light-shielding strip is often disposed on a side of the color filter substrate opposite to the array substrate and at a position corresponding to the black matrix, or the light-shielding strip is disposed between the second polarizer and the patterned retarder film and at a position corresponding to the black matrix. However, it may cause a decrease in the aperture ratio of the display device, resulting in a decrease in the brightness of the display device, thereby making the user see images of poor quality.